frexp(3C)
NAME
frexp − extract mantissa and exponent from double precision number
SYNOPSIS
#include <math.h>
double frexp(double num, int ∗exp);
DESCRIPTION
The frexp() function breaks a floating-point number into a normalised fraction and an integral power of 2. It stores the integer exponent in the int object pointed to by exp.
RETURN VALUES
The frexp() function returns the value x, such that x is a double with magnitude in the interval [½, 1) or 0, and num equals x times 2 raised to the power ∗exp.
If num is 0, both parts of the result are 0.
If num is NaN, NaN is returned and the value of ∗exp is unspecified.
If num is ±Inf, num is returned and the value of ∗exp is unspecified.
USAGE
An application wishing to check for error situations should set errno to 0 before calling frexp(). If errno is non-zero on return, or the return value is NaN, an error has occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| MT-Level | MT-Safe |
SEE ALSO
isnan(3M), ldexp(3C), modf(3C), attributes(5)
SunOS 5.6 — Last change: 29 Dec 1996